Method of lining contoured moulds and head boxes with deformable lining element

ABSTRACT

Ingot mould heads and head boxes are lined with slabs or sleeves of deformable lining material. The lower edge only of the slab or sleeve is deformed to fit tightly against the wall of the mould or head box and may be held in such deformed condition by means of a clip.

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[ 1 June 27, 1972 [54] METHOD OF LINING CONTOURED MOULDS AND HEAD BOXES WITH DEFORMABLE LINHNG ELEMENT [72] Inventors: Kenton Parkes Cooley; Edward John Jago,

both of Cleveland, Ohio [73] Assignee: Foseco International Limited, Birmingham,

England [22] Filed: Jan. 4, 1971 211 Appl. No.: 103,681

[30] Foreign Application Priority Data Jan. 6, 1970 Great Britain ..638/70 [52] US. Cl ..l64/6, 164/137, 249/106, 249/201 [51] Int. Cl ..B22d 7/10 [58] Field of Search 164/6, 137; 249/197-202, 106; 29/450; 220/63 R Primary Examiner-Rob ert D. Baldwin Attorney-Wolfe, Hubbard, Leydig, Voit & Osann [5 7] ABSTRACT Ingot mould heads and head boxes are lined with slabs or sleeves of deformable lining material. .The lower edge only of the slab or sleeve is deformed to fit tightly against the wall of the mould or head box and may be held in such deformed condition by means of a clip.

4 Claims, 2 Drawing Figures METHOD OF LINING CONTOURED MOULDS AND HEAD BOXES WITH DEFORMABLE LINTNG ELEMENT This invention relates to the production of ingots and more particularly to the hot topping of ingot molds.

It is common technique in the production of ingots, particularly steel ingots, to form the ingot in a mold which is provided at its head or in a head box secured to its head with a lining of a composition which will act as a barrier or hindrance to loss of heat from the molten metal at the head of the ingot mold or within the head box. Such a lining provides a so-called hot top to the ingot mold.

While for many purposes ingot molds are used of which the inner surfaces are essentially planar, it is also known to employ molds of which the inner surfaces are curved or corrugated. Such shaped molds may be used for the production of steel ingots of particular desired physical structure, the wall contour having an effect on the directional solification of the cast metal.

Clearly, in order to provide a-satisfactory hot top lining it is necessary to make the contour of the lining fit snugly against the walls which are to be lined, i.e., if the inner surface of the mold or head box is corrugated then the lining must be corrugated to conform with it. Such specially shaped lining slabs or sleeves are more difficult to make than planar slabs and are therefore less economical.

Turning to the drawings, there is illustrated exemplary em,- bodiments of the present invention, in which:

FIG. I is a fragmentary perspective view and illustrating a lining element adjacent the upper portion of an ingot mold;

FIG. 2 is a perspective view, partially broken away, and illustrating a lining element and a means for providing an outward deforming force.

The present invention is based on the discovery that provided the lower edge of the lining slabs or sleeve is made to fit snugly against that portion of the inner wall of the mold or head box which it is designed to contact, it is not necessary to cause the rest of the lined head or sleeve so to conform since the ferrostatic pressure of the molten metal will, if the material of the slab or sleeve is deformable, cause the slab or sleeve so to deform that it takes up the shape at which it fits snugly against the inner wall.

This technique is of general application, making it possible also to start with any shape which does not conform to the inner surface to be lined and cause it so to conform, e.g., a sleeve of circular cross-section may be deformed so that it fits snugly against the planar surface of a normal plane-sided mold.

According therefore to the present invention there is provided a method of lining the head of an ingot mold or of lining a headbox for an ingot mold which comprises locating within the mold or head box slabs or a sleeve of a deformable refractory composition, said slabs or sleeve having an outer contour which does not in its undeformed condition match the inner contour of the surface to be lined and securing the lower edges only of said slabs or sleeve to the said inner surface in such a way as to deform the lower edges and to cause said lower edges to conform to the contour of the surface to be lined.

In using the mold so lined and constructed, molten metal e.g., steel, as it fills the space within the lining causes, by hydraulic (metallostatic) pressure, the lining slabs or sleeve to be deformed to fit snugly against the inner surface of the mold or head box. In some instances it may be desirable partially to deform the slabs or sleeve by a forming device during the step of lining the mold or head box to ensure that complete wall contact is achieved. 7

If desired the slabs or sleeve used for lining the head box may extend below the head box structure so as to constitute a seal between the head box and the ingot mold on which it is placed.

Preferably, in order to give the required deformation, an expansible resilient metal band is located at the bottom edge of the lining material and is there sprung outwardly to deform the lining material against the walls of the mold or head box.

The slabs or sleeves used in the practice of the present invention may be of refractory heat insulating material or may be of an exothermic composition which on ignition by molten metal burns to leave a refractory heat-insulating residue.

In either event, and the former is generally preferable, the slabs or sleeve must be deformable under pressure. Suitable heat insulating refractory slabs having the desired degree of deformability may be constructed from compositions which comprise, in addition to a refractory particulate material a substantial proportion of fibrous material.

Suitable particulate refractory materials are: sand, zircon, calcined dolomite, cha'motte, alumina, magnesia and various silicates. The fibrous component is conveniently asbestos but where use of asbestos is undesired for health reasons it is possible to replace the asbestos wholly or in part by synthetic refractory fibers such as glass wool, slag wool and aluminum silicate fibers. The fibers may also be of metal e.g., a ferrous metal wool. Organic fibrous materials may also be employed, e.g., of cotton or synthetic materials such as rayon, acrylonitrile fiber, nylon fibers, polyester fibers and other synthetic textile fibers. Additional deformability is also achieved by including a proportion of very short fiber material such as cellulose fiber, e.g., paper pulp. Mixtures of any of the foregoing may be used.

A binder for aforesaid ingredients may be provided, e.g., a synthetic resin such as a phenol-formaldehyde resincor sodium silicate or silica gel, but is generally not necessary.

The precise composition of the slabs or sleeves will be chosen with respect to the pressure likely to be developed by the molten metal, compositions of high effective deformability being required if the developed pressure is not likely to be large, and vice versa. The compositions may in general contain the following ingredients in the proportions stated:

2-50 parts by weight 0.540 parts by weight 0-40 parts by weight 0-15 parts by weight The lower edges of the slabs or sleeves are conveniently caused to take up the contour of the inner surface by the provision of a metal strip itself of the desired contour that is pushed out during the fitting of the hot top into the mold or head box by some mechanical means, but does not have to be left in place during the pour.

The structure characteristic of the present invention is illustrated very diagrammatically in the accompanying drawing (FIG. 1) which shows a part only of the wall of an ingot mold having a corrugated inner surface. The part of the mold is shown at 1 and its corrugated inner surface at 2. A lining slab 3 has at its lower end a pre-contoured metal strip 4 which deforms the lower edge of the slab so that it conforms to the corrugations 2 of the mold wall, this strip either being left in position or removed before pouring commences. The remainder of the slab 3 stands free from the wall corrugations 2 but when molten metal is poured into the mold so that it is against the lining slab 3 the metallostatic pressure developed causes the whole slab to take up a corrugated shape and so conform to the surface corrugations 2.

One convenient method of providing the outward deforming force needed to deform the edge of the slabs or sleeve into contact with the mold or head box wall is a loop of stiff spring wire 30 as illustrated in FIG. 2. The wire is forced out against the sleeve 31 to deform it into contact with the mold or head box walls and then held in place by tying at 32. This method is particularly applicable to contoured but not corrugated molds.

We claim as our invention:

1. In the lining of the heads of ingot molds and lining head boxes for ingot molds wherein molten metal contacts a lining element, the method which comprises locating within the mold or head box at least one lining element selected from the class consisting of lining slabs and sleeves of a deformable refractory composition, said lining element being in an undeformed condition having an outer contour which does not match the inner contour of the surface to be lined, and securing the lower edges only of said lining element to the said inner surface by applying force in such a way as to deform the lower edges to cause them to conform to the contour of the surface to be lined leaving that portion of the lining element above the lower edges in a position to be deformed to the contour of the surface being lined by the metallostatic pressure of the molten metal contacting the lining element.

2. The method of claim 1 wherein a head box is to be lined,

and wherein a forming device is used to apply said force.

3. The method of claim 1 wherein a head box is to be lined, and wherein the lining element extends below so as the head box to form a seal between the head box and the ingot mold body when placed thereon.

4. The method of claim 1 wherein an expansible resilient metal band is located at the bottom edge of the lining element and is there sprung outwardly to apply said force to deform the lower edge of the lining element against the walls of the mold or head box. 

1. In the lining of the heads of ingot molds and lining head boxes for ingot molds wherein molten metal contacts a lining element, the method which comprises locating within the mold or head box at least one lining element selected from the class consisting of lining slabs and sleeves of a deformable refractory composition, said lining element being in an undeformed condition having an outer contour which does not match the inner contour of the surface to be lined, and securing the lower edges only of said lining element to the said inner surface by applying force in such a way as to deform the lower edges to cause them to conform to the contour of the surface to be lined leaving that portion of the lining element above the lower edges in a position to be deformed to the contour of the surface being lined by the metallostatic pressure of the molten metal contacting the lining element.
 2. The method of claim 1 wherein a head box is to be lined, and wherein a forming device is used to apply said force.
 3. The method of claim 1 wherein a head box is to be lined, and wherein the lining element extends below so as the head box to form a seal between the head box and the ingot mold body when placed thereon.
 4. The method of claim 1 wherein an expansible resilient metal band is located at the bottom edge of the lining element and is there sprung outwardly to apply said force to deform the lower edge of the lining element against the walls of the mold or head box. 